MINOR: session: export session_expire_embryonic()

This is only to make it resolve nicely in "show tasks".
diff --git a/src/session.c b/src/session.c
index 07828df..055b578 100644
--- a/src/session.c
+++ b/src/session.c
@@ -28,7 +28,6 @@
 		sizeof(struct sess_srv_list));
 
 int conn_complete_session(struct connection *conn);
-static struct task *session_expire_embryonic(struct task *t, void *context, unsigned short state);
 
 /* Create a a new session and assign it to frontend <fe>, listener <li>,
  * origin <origin>, set the current date and clear the stick counters pointers.
@@ -376,9 +375,10 @@
 }
 
 /* Manages the embryonic session timeout. It is only called when the timeout
- * strikes and performs the required cleanup.
+ * strikes and performs the required cleanup. It's only exported to make it
+ * resolve in "show tasks".
  */
-static struct task *session_expire_embryonic(struct task *t, void *context, unsigned short state)
+struct task *session_expire_embryonic(struct task *t, void *context, unsigned short state)
 {
 	struct session *sess = context;
 
diff --git a/src/tools.c b/src/tools.c
index 8891d47..4ad6b95 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -4699,6 +4699,7 @@
 		{ .func = listener_accept, .name = "listener_accept" },
 		{ .func = poller_pipe_io_handler, .name = "poller_pipe_io_handler" },
 		{ .func = mworker_accept_wrapper, .name = "mworker_accept_wrapper" },
+		{ .func = session_expire_embryonic, .name = "session_expire_embryonic" },
 #ifdef USE_THREAD
 		{ .func = accept_queue_process, .name = "accept_queue_process" },
 #endif